1. Field of the Invention
The present invention generally relates to computer software. More specifically, the present invention relates to computer aided design (CAD) software applications used to create and edit elements of a utility network represented in a CAD model.
2. Description of the Related Art
Currently, computer aided design (CAD) applications allow a designer or engineer to compose graphical representations of utility networks. For example, a user interacting with a CAD application may generate a model of a utility network by drawing simple 2D objects to represent components such as pipes, conduits, manhole covers, etc. Common 2D drawing objects include simple lines and arcs, etc., which provide only a crude representation of the network parts and do not adequately portray the real-world parts. To modify the utility network represented by the 2D drawing objects, the designer or engineer may have to edit one or more of these lines and arcs individually. To indicate connectivity, the user positions these 2D drawing objects relative to one another. If a part was moved that used to be positioned next to other parts to indicate connectivity, those other parts may also need to be individually moved. The process of modifying 2D drawing objects in a network is both time consuming and error-prone.
Some CAD applications are available that provide users with a predefined catalog of network parts used to compose a CAD model of a utility network. Such a parts catalog typically includes parts that represent elements of real-world utility networks. For example, a parts catalog may include parts such as pipes, structures, and fittings. Additionally, each part may be associated with a set of attributes. For example, the catalog may specify a variety of pipe parts, each representing a pipe with a different radius (e.g., 2″ pipe, 4″ pipe, etc.). Such a catalog provides a convenient method for users to compose a CAD model. However, once an instance of a part is included in a particular CAD model, changing the properties for that part may be difficult. For example, to change from a 2″ pipe to a 4″ pipe may require the user to delete the affected parts from the CAD model and replace them with the desired ones. Further, connections to structures, elevation positions within a digital terrain model, and length attributes may all have to be updated as well. This process can become quite time consuming for a user to make even simple changes to a CAD model. At the same time, these types of changes are frequently required as requirements for a project evolve during a design-build cycle.
Accordingly, there is a need for techniques that allow users to easily edit and modify network parts included in a CAD model of utility network.